Apparatus for constructing movable coils of electrical measuring instruments.



No. 678,708. Patented luly |s,|9m.

E. wasvou. APPARATUS FOR CONSTRUGTING MOVABLE CUILS OF ELECTRICAL MEASURING INSTRUMENTS.

(Application filed Dec. 18, 1899.) (No Model.) 3 Sheets-Sheet l.

J 1 wa 4 N0. 678,708. Patented July I6, [90'- E. WESTON. APPARATUS FOR CONSTRUBTING MOVABLE CUILS OF ELECTRICAL MEASURING INSTRUMENTS.

(Appliclfion filed Dec. 18, 1899.) (No Model.) 3 Sheets-Sheet 2.

T T T i T T m LFVN k1 1A u .vN i LKW Y S Patented July 56, IBM. E. WESTON.

APPARATUS FOR CONSTRUCTING MOVABLE COILS 0F ELECTRICAL MEASURING INSTRUMENTS. (Applicatibn filed. Dec. 18, 1899.)

3 Sheats$haet 3.

(No Model.)

Iilih in a 1 I mouiiiiiiiiun lflibiewwem m: "cams PETERS c'o, PHOTO-LITHO,WA5NINGTON. n.0,

llivrTnn STATES "PATENT @rrrcn.

EDYVARD WESTON, OF NEWARK, NEvV JERSEY.

APPARATUS FOR CONSTRUCTING MOVABLE COlLS OF ELECTRICAL MEASURING INSTRUMENTS.

$PEGIFICA'IIOH forming part of Letters Patent No. 678,708, dated July 16, 1901.

Application filed December 18, 1899. Serial No. 740,843. (No model.)

T0 at whom (It may concern:

Be it known that I, EDWARD WEsToN, a subject of the Queen of Great Britain, residing at Newark, in the county of Essex and State of New Jersey, have made a new and useful Invention in Apparatus for Manufacturing or Constructing the Movable Coils of Electrical Measuring Instruments, of which the following is a specification.

My invention is directed particularly to novel means for forming or constructing movable coils for electrical measuring instruments-such, for instance, as is shown in Figure 2 of the drawings and described in the specification of United States Patent No. 611,722, granted to me on the 4th day of October, 1898--and it has for its objects, first, the construction of a movable coil which shall be absolutely symmetrical in all of its parts and of the lightest practical available structure; second, the construction of a supporting frame or spool for coils of this type of a single piece of material without joint or seam and simultaneously giving to the lateral or side faces of said supporting frame or spool a curvature.

which shall be mathematically concentric with the curvature of the field-magnet poles which inclose it, and, third, the centering of the pivots which support such coils when in use in such manner that they shall be located in the axial line of the completed coil, and also that the needle supporting pivot shall have a fixed relation to the coil, which will always render it certain that the index-needle carried thereby shall be in a plane passing through the mathematical axis of the coil.

My invention will be fully understood by referring to the accompanying drawings, in which Fig. 1 illustrates in elevational View a thin metallic tube, preferably of drawn alumininm, from which the supporting frames or spools of the coils are cut in sections, as shown in dotted lines, Fig. 2 being a perspective View of one of such sections. Fig. 3 is a perspective view of a rectangular-shaped forming-mandrel for giving to the supporting frame or spool the desired initial configuration, as shown in dotted lines. Fig. at is a plan view of the forming-frame and the portable sectional forming and supporting core with one of the supporting frames or spools in place between said parts, illustrating the method of the formation thereof, the lower end of said frame being shown in broken sectional view for the purpose of illustrating the separable nature of the two-part forming-frame, a burnishing-tool being also illustrated in perspective view as it is used in turning down the lateral edges of the sup- 6o porting frame or spool. Fig. 5 is a plan view similar to Fig. 4, illustrating the method of completing the formation of the supporting frame or spool after the buruishing-tool has been utilized in turning down the lateral edges of the tube. Fig. 6 is a sectional view on the line y 11 Fig. 4, and as seen looL- ing thereat from the bot-tom toward the top of the drawings in the direction of the arrows, the burnishing tool being omitted. Fig. 7 is a plan view of the mechanism or means for-holding and manipulating the parts of the frame or spool forming apparatus, the latter being shown in position with the parts of the forming-frame slightlyseparated. Fig. 8 is a longitudinal sectional view thereof taken on the line a: x, Fig.7, and as seen looking thereat from the bottom toward the top of the drawings in the direction of the arrows. Fig. 9 is a part plan part perspec- 8o tive view of the apparatus for securing the pivots to the completed coil and in the axial line thereof and also for properly locating the shouldered pivot which supports the indexneedle in such manner that the point of the latter will be in the central plane of the coil or in a plane bearing a definite relation to the axis thereof, the holding device for securing the frame in a definite or fixed position with relation to the axis of the pivot- 0 supporting rods being shown in an open position, the completed coil, with its portable sectional forming and supporting core, being shown in dotted lines. Fig. 10 is a side elevational view of the same apparatus shown 5 in Fig. 9, illustrating the holding device in a closed position and the supported coil in dotted lines. Fig. 10 is a detail elevational view of that one of the pivot-supporting rods which aids in the securing of the needle-sup- 10o porting pivot in proper position. Fig. 11 is a transverse sectional view taken through Fig. 10 on the line a z and as seen looking thereat from the left toward the right-hand side of the drawings in the direction of the arrows. Fig. 12 is a side elevational View of the completed coil after the portable sectional forming and supporting core has been removed. Fig. 13 is an end elevational view of the same as seen looking at Fig. 12 from the right toward the left-hand side of the drawings, the index-needle being shown in position in this figure in dotted lines, the supported coil of a single layer of insulated wire being shown in sectional view.

In prior patents, Nos. 392,385 and 470,340, granted tome, respectively, on the 6th day of November, 1888, and 8th day of March, 1892, I have described and shown novel forms of movable coils for electrical measuring instruments and novel methods of and means for constructing the same, the former being constructed by first forming a coil of insulated wire upon a rectangular-shaped forming-mandrel, afterward removing the mandrel and placing about the coil a coating of electrodeposited copper, the latter by winding an insulated coil in a number of layers around .a mandrel and uniting the same together with shellac, afterward drying the completed coil and securing to the opposite sides thereof the pivot-pins. Such structures, however, are both open to the objection that in the handling or manipulating of the coils there is great danger of varying their symmetry, and there is also a further objection in that the dimensions of both of these forms of coils are such as to make it impractical to give to them a minimum cross-sectional area, a feature of great importance, as is disclosed in my Patent No. 611,722, above referred to.

My present invention is directed to novel means for forming coils of minimum weight, like that disclosed in the before-mentioned Patent No. 611,722, and also novel means for centering the supporting-pivots thereof in such manner that they shall be located directly in the mathematical axis of the coil.

Referring now to the drawings in detail, T, Fig. 1, represents a thin-drawn metallic tube, preferably of aluminium, from the end of which are out successively short sections I, Fig. 2, of the desired length, each to constitute the supporting frame or spool for the coil when formed as hereinafter described.

T, Fig. 3, represents a rectangular-shaped forming-mandrel with rounded corners adapted to give to the short sections of tube I the proper initial configuration, as shown in dotted lines.

F and F represent duplicate halves of a separable forming-frame detachably united together by pins 13 (See Fig. 4.) In the adjacent parts of this formingframe is cut outa rectangular-shaped opening with rounded corners, the end faces of saidopening being located in parallel planes, while the inner lateral faces thereof are curved concave, as shown in Fig. 6, to correspond to the curvature of the space between the field-magnet poles and the stationary soft-iron magnetizable cylinder which constitutes the magnetic field of an electrical measuring instrument' such, for instance,'as is shown in my Patent No. 611,722, above referred to.

A A K constitute the three individual sectional parts of a portable forming and supporting core for the frame or spool, the op-- posite ends of said sectional parts being parallel with the corresponding inner ends of the separable forming-frame F F and the outer lateral faces thereof curved convex, so as to be concentric with the corresponding concave curved portions of said forming-frame F F. The inner face of the sectional part A is parallel with the outer face of the forming-frame F, while the corresponding inner face of the sectional part A is in a plane located at an angle thereto, and the corresponding faces of the central sectional part K are in similar planes, the arrangement being such that in the act of putting the parts together there is a wedge-like action forcing aside the part A.

In a curvilinear recess in the upper surface of the sectional part K is secured by screws Z Z a disk j, the lateral edges of which are adapted to fit accurately in corresponding semicircular recesses in the upper faces of the sectional parts A A when in its lower position, the arrangement being such that when the parts are fitted together, as shown in Fig. 6, the upper surface of the disk j is flush with the upper surfaces of the parts A A K t' is a hole or opening extending entirely through the central sectional part K and disk j and is located in the absolute mathematical center of the sectional portable core when the parts are grouped together in the manner shown in Figs. 4, 5, and 6.

d d d d are four cone-shaped depressions drilled with mathematical nicety in the faces of the sectional parts A A, the function of which will be described later in connection with the description of the method of cen tering the pivot-supports of the coil.

1), Figs. 4: and 5, is a burnishiug-tool, the function of which will be described in connection with the description of the method of operation.

Referring now to Figs. 7 and 8, B repre sents the metallic base of the mechanism for holding and manipulating the parts of the frame or spool forming apparatus already described in connection with Figs. 4, 5, and 6 and illustrated in position in said base in plan view in Fig. 7 and in sectional view in Fig. 8, said base being secured to a bench or table by screws extending through screwholes 9 g g g. B and B are metallic blocks provided with shoulders orledges c 0, adapted to overlap the edges of the separable formingframe F F, the block B being held rigidly by a screw-bolt n and the block B adjustably by a screw-bolt n and Washer 8, having a neck extending upward through an oblong slot h in the base B, the arrangement being such that it (the block) may be moved back IIO and forth. E is an eccentric pivotally supported at one end of the base B by a bolt M, nut N and washer w and adapted to be rotated in the direction of the arrow by an operating-handle H. B is a metallic block adapted to be removably located between the block 13 and the eccentric E and to slide between guideways in the direction of the arrow when the eccentric is moved from left to right through the agency of the handle H, the right-hand end of the block B resting normally against the sliding block B N is a rectangular-shaped metallic block resting upon the base 13 and having on its upper surface a rectangular projection N of substantially the same contour as the frame or spool I and the sectional forming and supporting core A A K the arrangement being such that when the frame or spool I is in position to be formed, as shown in Fig. 8, its lower edge will surround the upward projection N. p is a centering-pin in the center of the block N, its function being to enter the hole or opening 2' of the portable sectional forming and supporting core, the arrangement of the parts being such that the axial center of the centering-pin is at equal distances from the curvilinear surfaces of the separable twopart forming-frame F F when the latter is in the closed position shown in Figs. 4 and 5. There may be any number of such pins and holes; but one of each is sufficient. wedging-tool adapted to be operated with a mallet or hammer and having at its lower end an oblong-shaped extension similar in general contour to the sectional part K (illustrated in cross-section in Fig. 6,) but of somewhat smaller dimensions, for first spreading the sectional parts of the forming and supporting core A A, as illustrated in Fig. 8, the face I) on one side corresponding to the similar face of the part A and the face I) to the similar face of the part A, q being a centering hole or opening in said tool corresponding to the hole or opening 1 in the central sectional part K (Illustrated in Figs. tand 5.)

Referring now to Figs. 9 to 11, inclusive, I will describe the apparatus for the centering of the pivots which support the completed coil when in use in an instrument in such manner that they shall be located in the axial line of the coil and also for properly locating and securing the shouldered pivot which supports the index-needle in such manner that the point of the latter will be in the central plane of the coil or in a plane having a definite angular relation thereto. F is the sup porting'frame of the apparatus, made, preferably, of cast metal, and S S S S are four screws extending upward through screw-holes in said frame, their upper ends being coneshaped and adapted to fit with mathematical nicety in the corresponding cone-shaped depressions cl d d (Z of the sectional parts of the portable forming and supporting core illustrated in Figs. 4 and 5. mm m m are setscrews running laterally through the sides of is a' the frame and adapted to bear with their pointed inner ends against the lateral faces of the screws S S S S. s s are pivot-supporting rods provided at their-outer ends with milled rotating handles g g said rods being accuratelyjournaled in journal-bearings Q, Q in the opposite ends of the frame, the arrangement being such that their axial lines when extended coincide. The inner ends of the pivot-supporting rods 8 s are provided with screw-threaded holes '1', adapted to receive the screw-threaded pins p p, to which are attached the pivot-supporting plates L L, the arrangement of said parts being such that the rods .9 5 may be moved inward and outward and rotated at will, for a purpose to be hereinafter described. P is a holding device for looking or holding the completed coil and its supporting-frame in a definite position with relation to the axial lines of the pivotsupporting rods .9 s Said holding device is pivotally supported at one side of the frame upon a lug or extension Z and is provided with four downwardly-extending screws S S S S, located when in locked position directly above the cone-points of the four screws S S S S, as clearly shown in Fig. 11 of the drawings. w is a slot in the outer or free end of the holding device adapted to receive one end of a locking-link O, pivotally supported upon a lug or extension Z integral with the frame F, said locking-link 0 being provided at its upper end with screw-threads and a nut R for securing it firmly in position. E is a metallic sleeve adapted to slide over the inner end of the pivot-supporting rod .9 and having secured to its inner end a laterally-extending arm V, provided with a rectangular slot in alinement with the axis of said rod for receiving the lateral faces ff of the needlesupporting pivot K, Figs. 11, 12, and 13 The sleeve E is provided with a slot on one side, located when in the position shown in Fig. 10 in alinement with the corresponding slot 50, Fig. 10 and at the inner end of the pivotsupporting rod 8 when the latter is in the position shown in Fig. 9, the function of said slots being to receive the free end of a lockingspring 5 secured to the outer end of the arm V. D is a metallic block secured to the frame F and adapted to sustain the free end of the arm V when rotated into the position shown in Fig. 11, the function of this part of the apparatus being to so locate that pivotpoint which supports the index-needle P that the latter will be in the axial plane of the coil, as clearly illustrated in dotted lines in Fig. 13, or at anypredetermincd angle, as may be desired.

Referring now to Figs. 1 to 8, inclusive, I will describe first the method of operation in manufacturing the supporting frame or spool. The short lengths of tubing which are to constitute the frames orspools I are cut from the tube T and afterward annealed in any preferred manner to the desired hardness for the purpose of preventing cracking or rupdotted lines in Fig. 6.

turin g of the edges when the latter are turned down with the burnishing-tool, so as to constitute the side flanges. These short sections of tubing are then placed upon the formingmandrel T and forced thereover to a definite point, as indicated in dotted lines, Fig. 3, so as to give to them the proper initial rectangu lar configuration. The block B, Figs. 7 and 8, is removed and the adjustable block B moved a sufficient distance to the left to permit of the insertion of the separable formingframe F F in position, with the parts separated, as shown in Fig. 7. The rectangular frame or spool I is now placed in position upon the block N around the projection N and the two sectional parts A and A of the forming and supporting core inserted, as shown in Fig. 8. The wedging-tool 7C is then inserted with the faces I) and b resting against the corresponding faces of the sectional parts A A of the portable forming and supporting core and with the pin 19 entering the centering hole or opening q. The tool is driven downward with a mallet or hammer, thus causing the sectional part A to be forced to the right against the inner right-hand face of the frame orspool I, the sectional part A remaining stationary. The block B is then put in place between the eccentric E and adjustable block B and the eccentric rotated from left to right in the direction of the arrow, through the agency of the handle H, thus causing the adjustable block B to firmly force the two parts of the forming-frame F F together and give to the frame or spool I a curvilinear shape. The tool is then removed and the sectional part 70 inserted and driven firmly home with a mallet or hamrner until the diskj is flush with the surfaces of the parts A and A, as clearly shown in Fig. 6 of the drawings, thus completing the curvilinear formation of the lateral or side faces of the supporting frame or spool and leaving the lateral edges 2? t thereof projecting at equal distances upon opposite sides and ends of the frame, as clearly shown in Figs. 4 and 6 of the drawings. The burnishing-tool b is now applied, as shown in Fig. 4, and the upper edge tis turned outward by the application of said tool, so as to constitute a flange, as clearly shown in Fig. 5 and in The eccentric E is now rotated in a reverse direction, the block B removed, and the adjustable block 13 withdrawn a sufficient distance to permit the forming-frame F F to be withdrawn and reversed, after which the block B is restored and the eccentric again rotated from left to right, causing the adjustable block B to restore the pressure upon the two-part formingframe and the inclosed supporting frame or spool. The burnishing-tool is then applied to the projecting edge 25, and the same is turned down, so as to.constitute the other flange, as clearly shown in dotted lines, Fig. 6 of the drawings. The block B is then removed and the adjustable block 13 Withherein described.

drawn, after which the parts of the forming-frame are separated a sufficient distance to permit of the removal of the completed supporting frame or spool and its portable forming and supporting core. The outer edges of the flanges t t are now trimmed upon a trimming-machine, which leaves upon the sides and ends flanges of the desired depth, such trimming device being so adjusted as to always leave like flanges for coils designed for a special type of instrument. The completed supporting frame or spool and its portable forming and supporting core are now placed upon a lathe with the rotary part thereof extending through the centering hole or opening t', and the coil of insulated wire H is accurately wound thereon,- preferably in a single layer, as clearly shown in Fig. 13 of the drawings. I am en abled with this apparatus or means to con struct a supporting frame or spool for the movable coil of an electrical measuring instrument which shall be mathematically symmetrical in all of its parts, and by reason of the fact that the portable forming and supporting core is left in position until after the coil is wound thereon there is no danger of varying the symmetry thereof. Furthermore, the insulated wire may be wound thereon under a tension which would not be possible in the use of delicate frames or spools like those It is also possible for me to place upon such supporting frames or spools absolutely the same amount of wire for a given number of turns, thereby assuring such a structure that the movable coils of all similar instruments shall be the exact duplicates of each other.

Referring now to'Figs. 9 to 13, inclusive, I will describe my novel apparatus or means for securing the coil-supporting pivot-pins to the ends of the completed coil in such manner that their axes shall be mathematically in alinement with each other and coincident with the mathematical axis of the coil itself. In the construction of the apparatus illustrated in Fig. 9 it will be understood that the axial lines of the pivot-supporting rods .9 s are coincident with each other and pass through a line midway between the points of the screws S S S S and that said screws are so adjusted in the frame F that said axial line will be in the mathematical center of the forming and supporting core when the latter is placed thereon with the points of the screws extending upward into the depressions d d d d, (see Figs. 4c and 5,) and that after said adjustment is effected said screws are firmly secured by the set-screws m m 'm m, so that their position whenever determined shall be constant. It will also be understood that when the portable forming and supporting core is in position and the holding device P in its lower or locked position the points of the screws S S S S are in a plane parallel with a plane passing through the extreme points of the screws S S S S and adapted to bear all firmly upon the upper surface of the forming and supporting core. In other words, the points of the coned screws when properly adjusted are all in a common plane and support the forming and supporting core with a definite or fixed relation to the axes of the pivot-supporting rods .9 s and the screws S S S S and locking-link O with locking-nut R will when secured in the manner shown in Fig. 10 maintain or hold said parts firmly in a definite relation to the portable forming and supporting core and the frame or spool and coil carried thereby. The pivotsupporting plate L and lower pivot-pin K are now detachablysecured to the inner end of the pivot supporting rod by means of the screw-threads 19, after which the inner surface of said plate is covered with a definite amount of cement and the pivot-supporting rod 5 is rotated in such direction as will bring the lateral edges of the plate L parallel with the end flanges of the supporting frame or spool I. The rod 3 is then forced longitudinally inward from left to right until the plate L is held firmly against the face of the coil H, thereby connecting the pivot to the coil andits supporting frame or spool I. The needle-supporting pivot K requires a more accurate adjustmentin order that the lateral faces ff may bear a fixed relation to the frame or spool and its supported coil. To effect this, said pin is inserted in the rectangular slot or opening in the inner end of the sleeve E, said faces being absolutely parallel with the lateral faces of the arm V. The sleeve E, with its supported pivot pin and plate L, is now placed in position with the pivot-pin in alinement with the screw-hole r in the inner end of the supporting-rod s, and the latter is rotated from left to right until the locking-spring the free end of which rests in the slot of the sleeve E, falls into the concentric slot 00, thereby locking the parts together. When this occurs and the parts are securely held together by the screw-threads p of the pin and the corresponding screw-threads at the inner end of said rod, the upper end of the arm V rests upon the upper surface of the block D, which is of such a thickness that when said arm is in this position the lateral faces ff of the pivot-pin K are absolutely parallel with the the lateral edges ofthe supporting frame or spool I. (See Figs. 11 and 13.) The inner surface of the plate L'is then coated with cement and the pivot-supporting rod 3 forced longitudinally inward from right to left until theplate L is held firmly against the face of the coil H, thereby securing the pivot to the coil and its supporting frame or spool I. The completed coil is left in this position until the cement is thoroughly dry. The portable sectional supporting-core is not removed until it becomes necessary to place the coil in position in a completed instrument, said core acting as a means of maintaining it (the coil) and its supporting frame or spool I in perfect condition without danger of being injured. When the coil is required for use, the pivot-supporting rods are detached from the pivot-pins by rotating them in proper direction and the portable sectional supportingcore is removed. The coil is then put in position in the instrument for which it is designed.

Although I have shown and described the frame or spool and supported coil as of rectangular form, it is obvious that it may be of any desired form, as circular, triangular, or, in fact, such form as the shape of the fieldmagnets between or before which it is designed to rotate may necessitate.

I do not limit myself to the especial means hereinbefore described and illustrated in the accompanying drawings for effecting the results sought, as I believe it is broadly new with me to provide means for constructing a supporting frame or spool for an electrical coil of a single piece of metal without joint or seam and in such manner that said supporting frame or spool shall be symmetrical in all of its parts and that it is new with me to utilize a portable core for forming and supporting the frame or spool of an electrical coil and winding thereon the insulated wire and finally centering thesupporting-pivots upon the coil in the axial line thereof through the agency of such forming and supporting core, and my claims are generic as to these features.

I make no claim in the present application to the method of forming a supporting frame or spool for the movable coil of an electrical measuring instrument and centering the supporting-pivots upon said coil through the agency of a forming and supporting core when held in a fixed position with relation to means for securing the pivots thereto and in the axial line thereof, nor to the method of locating the pivot which supports the indexneedle with such relation to the coil that the point of the supported needle shall be always in a plane passing through the center of the coil or in a plane having a definite relation thereto, as these features constitute the subject-matter of a separate application hearing Serial No. 738,377, filed in the United States Patent Office on the 27th day of November, 1899; nor do I claim in the present application an article of manufacture con sisting of a frame or spool and a coil wound thereon, said parts being supported by a de tachable or removable core; nor do I claim herein an article of manufacture consisting of a frame or spool, a coil wound thereon, and one or more pivot-pins secured thereto, together with a detachable or removable core supporting all of said parts, as this subjectmatter is embraced in a divisional application bearing Serial No. 62,833, filed by me in the United States Patent Office on the 3d day of June, 1901.

Having thus described my invention, what I claim, and desire to secure by Letters Patent of the United States, is-

1. Means for forming or constructing the supportingilframe or spool of. a movable coil for an electrical measuring instrument, consisting of a separable forming-frame and a portable forming and supporting core, said frame and core being adapted,when subjected to pressure, to give to the coil-supporting frame or spool, when placed between them, the desired configuration or shape, substantially as described.

2. Means for forming or constructing the supporting frame or spool of a movable coil for an electrical measuring instrument, consisting of a separable forming-frame and a portable sectional forming and supporting core, said frame and core being adapted,when subjected to pressure, to give to the coil-supporting frame or spool, when placed between them, the desired configuration or shape, substantially as described.

3. Means for forming or constructing the supporting frame or spool of a movable coil for an electrical measuring instrument, consisting of a separable forming-frame and a portable sectional forming and supporting core, in combination With means for forcing the parts of the separable frame together and additional means for separating or spreading the parts of the. sectional forming and supporting core, substantially as described.

4. Means for forming or constructing the supporting frame or spool of a movable coil for an electrical measuring instrument, consisting of a separable forming-frame, the innerlateral faces of which are of concave form; in combination with a portable sectional forming and supporting core, the outer lateral faces of which are of convex form, together with means for causing said frame and core to give to the coil-supporting frame, when placed between them, the desired configuration or shape and curvature, substantially as described.

5. A portable forming and supporting core for the supporting frame or spool of an electrical measuring instrument composed of three sectional parts, the exterior faces of the outer parts being of convex form, the central part being provided with means for separat- '7. Means for forming or constructing the supporting frame or spool of a movable coil for an electrical measuring instrument, consisting of a separable forming-frame and a removable sectional forming and supporting core adapted to be located between the parts of the forming-frame, in combination with means for holding and manipulating the separable frame and the inolosed forming and supporting core, the arrangement being such that a short section of metallic tube may be inserted between the separable frame and the forming and supporting core and subjected to pressure so as to give to the frame or spool the desired configuration or shape; together with means for turning down the lateral edges of the tube so as to constitute the flanges of the completed frame or spool, substantially as described.

8. Apparatus for securing the pivots to the movable coil of an electrical measuring instrument consisting of means for locking or securing the coil in a definite or fixed position with relation to a coil-supporting frame, in combination With pivot-supporting means for properly alining the pivots in the axial line of the coil, said pivot-supporting means having a fixed relation to the supportingframe and its supported coil, substantially as described. 1

9. Means for properly alining the supporting-pivots of the movable coil of an electrical measuring instrument in such manner that they shall be secured thereto in the axial line thereof, consisting of a supporting-frame provided with means for adjustably supporting the coil with relation thereto; in combination with means for locking the coil in a fixed po-' sition, together with pivot-supporting means secured to the frame and detachably supporting the pivot-pins in alinement with each other and in the axis of the supported coil, substantially as described.

10. Means for properly alining the pivots of the movable coil of an electrical measuring instrument consisting of a coil-supporting core and a frame provided with means for supporting the core and the coil carried thereby in a definite relation thereto, together with means for locking said core in such relation; in combination with pivot-supporting rods located in alinement with the axis of the core and its sustained coil, said rods being provided with means for detachably supporting the pivots, substantially as described.

11. Means for properly alining the needlesupporting pivot of the movable coil of an electrical measuring instrument, and adj usting the angular relation of the supported needle, consisting of a coil-supporting core, a frame vprovided with adjustable means for supporting the core and means for locking the latter in a fixed relation to the frame; together with a pivot-supporting rod secured to the frame and in alinement with the axis of the coil; in combination with means for scribed my name this 22d day of November, locating the lateral faces of the needle-sup- 1899. porting pivot in planes parallel with a plane passing through the center of the coil, or in EDVARD 5 planes having a definite angular relation Witnesses:

thereto, substantially as described. C. J KINTNER, In testimony whereof I have hereunto sub- 1 W. H. MOORE. 

